1. Field of the Invention
The present invention relates to a bead core for a pneumatic vehicle tire that is designed to have its beads disposed on the radially inner periphery of a rim. The bead core is in the form of an endless ring that has an essentially round cross-sectional shape.
2. Description of the Prior Art
A vehicle tire having such a round bead core is described, for example, in German Offenlegungsschrift No. 30 00 428 Rach et al dated July 9, 1981 and belonging to the assignee of the present invention. In contrast to the tires predominantly used these days, with a tire of this type the bead cores are subjected to only slight tensile stress, and to a great amount of compression. This was not taken into consideration in the tire disclosed in German Offenlegungsschrift No. 30 00 428 Rach et al dated July 9, 1981. A further problem frequently arises with vehicle wheel and tire assemblies where the tire beads are disposed on the radially inner periphery of the rim; the tire beads must be pivotable relative to the bead cores so that the tires can be mounted on a one-piece rim. This problem was considered in detail in German Offenlegungsschrift No. 32 44 046 Mauk et al corresponding to U.S. Pat. No. 4,597,426-Mauk et al issued July 1, 1986 belonging to the assignee of the present invention and in German Offenlegungsschrift 32 46 624 Frerichs et al dated June 20, 1984 belonging to the assignee of the present invention. And in German Offenlegungsschrift No. 34 40 440.6 Brunke dated May 7, 1986, it was proposed to interconnect the wires of the outer layer of a bead core ring by soldering them in order in this manner to achieve a high reliability during compression of the tire bead.
It is an object of the present invention to provide a bead core ring that can further optimize a vehicle tire, and in particular can increase the resistance to bending and can reduce the weight, while maintaining or even improving the bead seating reliability that has already been achieved.